Electric telemetering device



Aprll 25, 1950 c. A. DE GIERS 2,5@5,359

ELECTRIC TELEMETERING DEVICE Filed Nov. 21, 1946 2 Sheets-$heet l INVEN TOR. 0/. A E/v05 //.DE G/ERS ATTORNEY April 1950 c. A. DE GIERS 2,505,350

ELECTRIC TELEMETERING DEVICE Filed Nov. 21, 1946 2 Sheets-Sheet 2 Hum.,n lmmkl M IINVENTOR.

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Patented Apr. 2 1950 UNITED "STATE P E OFFICE 2,505,350 ELECTRIC m MEr nING-DEvIcE Clarence A. de Giers,,Forest Hills, N. Y., assignor to The Liquidometer Corporation, ongfl'sland City, }N. Y., --a corporationpf Delaware ApplicationNovember 21, 1946, Serial N0. 712L417 6 Claims. 11

This invention relates to atelemetering device forindicating and/or control purposesin which a transmitter including a variable resistor controlled by a variable physical magnitude to be supervisedtransmits corresponding signals to a receiver system. vThe invention relates particularly to a'transmitter systemin which the variable resistor is controlled by a change of the level of an inflammable or hazardous liquid, such as. fuel contained in a tank.

,Transmitter systems of the general type, above referred to, are usually mounted directly on the fueltank or closely adjacent thereto. As a re sult, there is a certain latent danger of an ignition ofv fuel fumes by electric sparks at the electric components ofthe transmitter systems. Such fueljfumes are. always present to ,a certain extent, as leakage of fumes from the tanki ractically unavoidable, particularly when a highly volatile fuel such as gasoline is contained in the tank. Furthermore, the presence of fuel fumes tends to corrode the metal parts of the transmittersystem, thereby impairing the reliability of the transmitter.

Accordingly, one of the objects of the invention is to, provide means which greatly reduce or even completely eliminate the danger of explosion by ignition of fuel fumes.

vAnotherobject of the invention is to provide means by which the electric partsof thetransmitter are substantially protected against contact with corrosive fuel. fumes.

Another. object of the invention is to provide meansby which the eifectof an explosionby ignition of fuel fumes, if such should occuris local izedand .prevented from extending into the tank proper.

Another .object of the invention is, to provide means causing a harmless dissipationof the pressure of an explosion, if such should occur, thereby protecting the transmitterand also preventing damage to, the. rather delicate seal conventionally employed toseal off the liquid level detestin p rts of. the transmitter-which extended into the tank proper.

Anotherobject of the invention resides in the provision of a substantially explosion and corrosion proof transmitter system of the general type, above referred to, which is ruggedand reliable in operation andinexpensivejin manufacture.

Other and further advantages, features, and objects of the invention will hereinafter appear and thenovel features thereof will be pointedout in the appended claims forming part of the application.

. In the accompanying drawings a now preferred 2 embodiment of the invention is shown by way of illustration and not by way of limitation.

lnthewdrawings: 0

Eig. l is. a sectionalside view of a transmitter system according to the invention.

Fig. 2 is asection along line 2-2 of Fig. 1, the parts of the transmitter system extended into thetank proper being omitted, and

Fig.3 is a side view of the parts shown in Fig. 2, the coverof the transmitter housing being rem e Referring now to the flgures in detail, the transmitter system according to the invention comprises a housing, generally designated ID. This housingis provided with a flange I! restingupon a flange l2 fastened thereto by any suitable means such as screw bolts I3 (see Fig. l). Flange i2 is threaded upon the upper end of a pipe Hi the lower end ofwhich is threaded into a flangel5 which in turn is fastened by any suitable means such as soldering to a wall I6 of a tank containing the hazardous liquid for instance'fuel, the content or level of which is to be measured by the transmitter system.

-The -liquid level is detected in a conventional manner by means of a float H floating on the liquid in the tank andfastened to a float arm I8. This float arm is pivoted to a bracket l9 by a pivot-20 supported by the bracket. Bracket I9 is threaded upon the lower end of a pipe 2|, the upper end of which is passedthrough pipe l4 and isthreaded into an opening 22 of flange ll. Extending through pipe- 2| is also a push-pull rod 23 the lower end of which is pivoted to float arm is by means ofa pivot24. 'As will be apparent, a swinging movement of float arm l8 about pivot 20 will cause an upward or downward axial displacement of rod 23, as the case may be. The upper end of rod-23 extends into housing I0 and supports a rod25 which is telesooped into rod 23 and can be adjustably fixed therein by means of a set-screw 2G; for adjustment of the length of the rod.

Rod 25 is pivoted to a slider 2? by a pivot 23. Slider 2? is islldably carried on one arm of a twoarm lever- 29 and can be fixed in its position by a set screwed-for the adjustment of movements transmitted by axial displacement of rod 23 to lever 29. A portion 34' ofthe housing may be removed to facilitate ccess to rod- 25. Lever 29 is pivoted to a bracket}! by a pivot 32. The bracketextends froma wall33 serving as a partition wall between a compartment 34 and a second compartment Partition wall 33 has an opening ts leaving sufficient clearance for a rocking movement of lever- 29 about pivot 32. As

will be apparent, openings 22 and 36 connect compartment 35 with the interior of tank Hi. In order to prevent fuel fumes from entering compartment 35 through these openings, opening 36 is sealed off b a flexible seal 31 of the bellows type. This seal is fastened at one end tightly to lever 29 and at the other end is tightly sealed to partition wall 33. Lever 29 passes through the bellows, the flexibility of the bellows walls permitting a rocking movement of lever 29.

The arm of two-arm lever 29 extended into compartment 35 is pivoted by a pivot 38 to a link 39, the end of lever 39 being arranged between two prongs of this link (see Fig. 2). The other end of link 39 is pivoted by a pivot 49 to a second or crank arm 4!, as can best be seen on Fig. 2. Arm 4! is rigidly fastened to a shaft 42. This shaft is extended into a third compartment 43 (see Fig. 2). Compartments 35 and 43 are separated by double partition walls 44 and 44'. These wall portions are joined by a hub 45 in which is provided an elongated bearing opening 46 through which shaft 112 is rotatably passed. The clearance between the shaft and the bearing is very small so that the shaft can just freely rotate within its bearing. Shaft 52, at its end extended into compartment 43, supports a third arm i) (see Fig. 3) rigidly fastened to the shaft. The outer end of arm 59 is pivoted to a link 5| by a pivot 52; the other end of this link is pivoted to another arm 53 by a pivot 54. Arm 53 is fastened to a shaft 55 rotatably supported by a socket 56 which in turn is supported by partition wall 44. Rigidly fastened to shaft 55 is the insulated portion 5? of a wiper arm, generally designated 58. Insulated portion 57 serves as support for a wiper contact 59 which is fastened to insulated member or portion 51 by screws or rivets 60 or other suitable means. Wiper 59 slidably engages an arcshaped resistance element BI.

As will be evident, an angular movement of shaft 42 in either direction will impart a corre- Spondlng angular movement to wiper 58 through the previously described linkage system. Resistance element 6! is tapped at points 62 and 64. These taps and also wiper contact 59 are connected by wires 55, El and 68 to a connector 69 positioned in a fourth compartment ill on the top wall of compartment 35. Connector 69 serves to connect the transmitter with the receiver system (not shown) of the telemetering device as indicated by wires H extending from connector 69.

The upper portion of partition wall 44 which separates compartments 43 and has an opening 12 through which pass the Wires connecting the elements El and 58 with the connector 69. Similarly, the wall portion of housing In forming an outer wall of compartment '50 has an opening 13 for wires ll. Openings i2 and '83 are tightly sealed by any suitable sealing material l4 and respectively so that compartment ill is completely closed.

To facilitate a replacement or repair of the elements 58, GI and the wires connected thereto, compartment 43 can be conveniently opened by removing a cover lb resting upon a collar ll of the compartment walls.

Compartment is provided with a vent, generally designated 78. This vent comprises a screw 19 having an axial hole 30 and extended into compartment 35. The inner end of screw 19 is covered with a perforated cap 8! or a cap made of porous material.

As will appear from the previous description and explanation of the drawings, an upward or downward movement of float ll due to a change of a liquid level to be detected will cause a corresponding angular movement of wiper arm 58 relative to resistance element 6|, thereby controlling signals sent by the transmitter to the receiver system when the telemetering device is operating. These varying signals are used to control the receiver system by means which are well known in the art and need not be described here in detail.

As previously mentioned, the main purpose of flexible seal 31 is to seal off the interior of compartment 35 and particularly shaft 42 against fuel fumes which may be present in compartment 34. Practical experience has shown that the corrosive effect of such fumes would soon render the entire transmitter inoperative due to seizing of the shaft in the small clearance between the shaft and bearing opening 46. On the other hand, the small clearance of the shaft bearing is necessary, to localize an explosion in compartment 43, if such should occur, and to protect the comparatively delicate bellows seal against an excessive explosion pressure.

Let it be assumed that fuel fumes have seeped into compartment 43, for instance by creeping into the compartment between cover 15 and the compartment walls, and that these fumes are ignited by a spark at the wiper contact. Then, a high explosion pressure will be built up rapidly in compartment 43. As compartment 43 is completely closed, except at bearing opening 46, the pressure wave will travel through the clearance between the shaft and its bearing. Due to the smallness of this clearance, the pressure in compartment 35 will be built up comparatively slowly so that it can be dissipated through vent 18 before it becomes high enough to damage seal 3?. On the other hand, the dissipation of the pressure through the clearance prevents damage to the transmitter housing and seal 14 due to excessive pressure in compartment 43.

The elongated shaft bearing 46 has the additional advantage that flaming material tending to travel from compartment 43 to compartment 35 is cooled off sufficiently during its passage through bearing 46 to be extinguished before reaching compartment 35.

As will appear from the previous specification, the specific arrangement of the bellows seal and shaft 42 results in a mutual protection of these two important components of the transmitter system. The seal protects the shaft and other parts of the transmitter system against the continuous corrosive effect of fuel fumes escaping from the tank, while the shaft and the small clearance of the shaft bearing protect the seal 3'! against the impact of high explosion pressure. As a result, the danger of an explosion is greatly reduced and the effect of an explosion, if such should occur, is substantially minimized.

While the invention has been described in detail with respect to a certain now preferred example and embodiment of the invention it will be understood by those skilled in the art after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended therefore, to cover all such changes and modifications in the appended claims.

What is claimed is:

1. Transmitter for a telemetering device of the character described, comprising a housing to be attached to a tank containing a hazardous liquid to be detected, solid partition walls disposed within the housing and dividing the same into several compartments, said housing and said partition walls separating each of said compartments from each other and from the atmosphere except as hereinafter set forth, a variable resistor mounted within one of said compartments, said resistor comprising a stationary element and a movable element, a linkage system having members operatively connected with the movable resistor element and capable of transmitting a change of the liquid level in a tank to the said resistor element for controlling the relative position of the resistor elements corresponding to the liquid level, one of said partition walls having an opening connecting the compartment containing the resistor with a second compartment containing members of the linkage system, a shaft member included in the linkage system and passed through said opening with a narrow clearance, a flexible seal constructed and positioned to seal the compartment containing members of the linkage system against the tank proper, and a Wall portion of the housing confining said second compartment having a permanently open vent hole continuously connecting the second said compartment with the atmosphere, thereby permitting the dissipation of pressure built up within the housing which may pass to said second compartment through said opening in the narrow clearance about said shaft.

2. Transmitter for a telemetering device of the character described comprising a housing adapted to be attached to a tank containing a hazardous liquid to be detected, solid partition Walls disposed within the housing and dividing the same into several compartments, a variable resistor mounted within one of said compartments, said resistor comprising a stationary element and a movable element, a linkage system operatively connected with the movable resistor element and capable of transmitting a, change of the liquid level in a tank to the said resistor element for controlling the relative position of the resistor elements corresponding to the liquid level, said linkage system including members positioned in the resistor compartment and other members positioned in a second compartment of the housing, the partition wall between said two compartments having a bearing opening connecting the same, a shaft operatively connecting the linkage members in the resistor compartment and in the second compartment and passed through said opening with a narrow clearance, and a flexible seal constructed and positioned to seal the second compartment and the linkage members extended therefrom against the tank proper.

3. Transmitter for a telemetering device of the character described comprising a housing adapted to be attached to a tank containing a hazardous liquid to be detected, solid partition Walls disposed within the housing and dividing the same into three compartments, a variable resistor mounted within one of said compartments, said resistor comprising a stationary element and a movable element, a linkage system operatively connected with the movable resistor element and capable of transmitting a change of the liquid level in a tank to the said resistor element for controlling the relative position of the resistor elements corresponding to the liquid level, said linkage system including members positioned in the resistor compartment and other members positioned in the second compartment of the housing, two partition walls between said two compartments having a closed annular sleeve therebetween providing an opening connecting said two compartments, a shaft operatively connecting the linkage members in the resistor compartment and in the second compartment and passed through said opening with a narrow clearance, a flexible seal constructed and positioned to seal the second compartment and the linkage members extended therefrom against the tank proper, and a connector electrically connected with the resistor elements, and adapted to be connected with the receiver system of a telernetering device, said connector positioned within the third compartment of the housing.

4. Transmitter for a telemetering device of the character described comprising a housing adapted to be attached to a tank containin a hazardous liquid to be detected, partition walls disposed Within the housing and dividing the same into several compartments, a variable resistor mounted within one of said compartments, said resistor comprising a stationary element and a movable element, a float capable of floating on a liquid level to be detected, a float arm supporting said float, a push-pull rod pivoted to the float arm and extended into a second compartment through an opening in the housing, support means fastened to the housing and pivotally supporting the float arm for causing said rod to be axially displaced in response to a float movement, a twoarm lever operatively connected with one arm to the rod so as to impart a rocking movement to said lever in response to an axial displacement of the rod, a rotatably supported shaft, a linkage system operatively connected to the other arm of the rocking lever and to one end of the shaft for imparting to the shaft a rotary movement in response to a rocking movement of said lever, a second linkage system operatively connected to the other end of the shaft and the movable resistor element for displacing the said element in response to a shaft rotation, thereby controlling the relative position of the resistor elements corresponding to the float position, said second linkage system positioned in a third compartment, the partition Wall separating the second and the third compartment having an opening through which said two-arm lever is extended, means for pivotally supporting said lever on the said partition wall, a flexible seal encompassing said lever partially and sealing off the third compartment against the second compartment and hence the housing against the tank proper.

5. Transmitter as described in claim 4, in combination with a connector electrically connected with the resistor elements and adapted to be connected with the receiver system of a telemetering device, said connector being positioned Within a fourth compartment of the housin formed by said partition walls.

6. Transmitter as described in claim 4 wherein a wall portion of the third compartment has a vent hole connecting the third compartment with the atmosphere, thereby permitting the dissipation of pressure built up within the housing.

CLARENCE A. DE GIERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,649,885 Adams et al. Nov. 22, 1927 2,283,378 Liner May 19, 1942 2,373,292 Clason Apr. 10, 1945 2,393,952 Austin Feb. 5, 1946 

